PH meter



FIG. 1 is a top plan, front and left side perspective view of a pH metershowing my new design;

FIG. 2 is a bottom plan, rear, and right side perspective view; and

FIG. 3 is a top plan, front, and left side perspective view of anotherembodiment of FIGS. 1 and 2 thereof.

The ornamental design for a pH meter, as shown.